Well... this is still weird, at least
But I´d rather wait for the game to be available and people check it by themselves instead of jumping on conclusions. We all know, by now, that the Switch accept headsets, so voice chat is a possibility on it alone. It´s not just clear how this "app" thing will work.
Personally, I don´t miss voice chat during Splatoon matches, but for people who wants to get competitive, it really lacks.